Vertical stapler



FIG. 1 is a lower front right perspective view of a vertical stapler showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof, with the right side elevation view being a minor image of the left side elevation view;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a vertical stapler, as shown and described. 